Fire extinguisher



Aug. 15, 1950 E. R. BORK 2,518,656

FIRE EXTINGUISHER Filed April 11, 1949 INVENTOR.

ATTORNEYS Patented Aug. 15, 1950 FIRE EXTINGUISHER Edward R. Bork, Dayton, Ohio, assignor to The Fyr-Fyter Company, Dayton, Ohio, a, corporation of Ohio ApplicationApril 11, 1949, Serial No. 86,691

This invention relates to fire extinguishers, and more particularly to a pressurezcartridge unit adapted for use in a fire extinguisher.

In fire extinguishers employing a pressure cartridge, it is a common practice for the cartridge to incorporate a removable cap which is secured on the cartridge and which incorporates a; frangible sealing disk overlying and normally sealing the outlet from the cartridge, together with the necessary piercing pin and associated mechanism to rupture the disk and meter the outflow of gas therefrom. Both the cartridge and the cap are relatively expensive and are usually returned in order to obtain a recharge. This necessitates not only the added expense of retumingthe cartridges and caps following each operationand the accompanying handling thereof by the manufacturer, but unless duplicate supplies 7 have been provided, makes the equipment inoperative during this interval. A typical construction of this type is that shown in the patent to Wright No. 1,976,056 issued to the assignee of this application.

The present invention relates to an extinguisher of this type, but in which the pressure cartridge is such that it need not be returned for recharge, being intended for a single use after which it may be thrown away. The cartridge incorporates a rupturing member which is fully and adequately enclosed and protected against access of moisture or other foreign matter prior to operation so that it retains its original sealed condition indefinitely and which affords proper and controlled metering of the flow of gas upon operation so that the desired pressure condition will be obtained throughout the operationwithout excessive pressure or objectionable freezing up of the gas outlet. In addition the construction is relatively simple and inexpensive and such that the entire device may economicallybe' discarded after a single use. Thus there is no necessity to return anything for recharge and by merely having spare charge available, the spent extinguisher may be immediately restored to operative condition.

It is accordingly one'of' the principal objects -.of thepresent invention to provide a pressure cartridge unit adapted for use in a fire extin-' guisher which is simple to produce and install, which is reliable in operation even after standby for long perods of time, and wherein the component parts are of simple construction such that the unit can bev produced economically-for onetime use and then disposed of without refilling.

Anotherobjectiof the invention is to provide 9 Claims. (Cl. 169-31) such a pressure cartridge unit which includes a metering orifice so located and arranged inthe unit that it is sealed against dirt and moisture at all times prior to use and is automatically opened for discharge simultaneously" with the opening of'the cartridge itself.

It is also an object of the invention to provide such a pressure cartridge unit which includes a plunger for rupturing and penetrating the cartridge to release the gas therefrom, and more particularly to provide such a unit wherein'the plunger includes an integral portion which seals against access of dirt and moisture to the metering orifice prior to use and which automatically moves from its sealing position allowing 'free outflow of the gas simultaneously with its-rupturing action. 'z

- Other objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims. a 1' In the drawing: I Fig. 1 is a view in side elevation, partly broken away and in vertical section, showing a fire extinguisher embodying a pressure cartridge unit constructed in accordance with the; present invention; v

Fig. 2 is a fragmentary and partially exploded section on a larger scale showing the pressure cartridge unit prior to opening of the cartridge;

Fig. 3 is a view similar to Fig. .2 showing .the pressure cartridge unit following opening of the cartridge. w

Fig. 4 is a detail view in elevation showing the plunger of the unit;

Fig. 5 is an end view of the plunger; and

Fig. 6 is an enlarged view of-afragment of Referring to the drawing, which illustrates a preferred embodiment of the, invention, Fig. 1 shows a fire extinguisher of the pressure cartridge type having a main casing In which is provided with a removable cap ll and'a flexible hose II. The pressure cartridge I3 is supported within casing ill in a suitable cage including a U-shaped strap l5 riveted to the supporting arms l6 of a socket member [1, this cage being clamped in operative position between the upper end- .of the casing l0 and the cap. ll. Thelower' end of cartridge l3 includes thefilling neck 20, and is received in an apertured plate 2|" which is slotted at opposite ends for sliding engagement with the sides of the strap l5 and. is supported on a, cup shaped member 22 carried by thumbupper end of the in Figs. 2 to 6. Referring to Figs. 2 and 6, the

upper end of the cartridge is coined to provide an integral web which is thinner than the. remaining walls of the cartridge and is readily rupturable to release the gas therefrom. A frustoconical surface 3i surrounds the upp Surface of web 30 to provide a lead-in taper to the web. A cup-shaped shell 33 is press-fitted, shrunk or otherwise secured at 34 over the upper end of the cartridge and extends beyond the cartridge to formra chamber 35 whichov'erlies the web 30, and this shcll'has a circular. hole 36 in the .end thereof which is opposite and substantially coaxial with the web 30. The upper endportion 3.! of shell 35 is of smaller diameter than the remainder of the shell to fit readily within the center aperture in socket member 11, the shell having a circum ierential shoulder 38 which limits the extent of its insertion in member 11.

A plunger 46 extends through the opening '35 in shell 33, and an intermediate portion of this plunger is cylindrical and of a proper diameter for press-fitting within the opening 38 to seal this opening as shown in Fig. 2. For example, sati's- 41 approximately equal to the thickness of shell.

33. An enlarged portion 42 of the plunger forms a circumferential shoulder 43 arranged to seat on the inner surface of the end wall of shell 33.

The plunger also includes an inner end "portion it which is of such diameter as to be capableof readily rupturing and penetrating the web 30 in the end of cartridge I3, the lower end of this plunger 44 being tapered at 45 to guide "the plunger in the rupturing operation. by cooperating with the lead-in taper 31 to the web. The 'phmger portion in is formed with a central bore It which communicates with a cross passage for releasing the gas from within cartridge #3 after rupture of web '30, the Cross passage having a narrow portion 41 immediately adjacent bore 46 "which forms a metering orifice leading 'into a radial bore 48 in the enlarged plunger portion 4 2. For example, the bores 86 and 48 may be is inch in diameter, with the metering passage 4'! having :afliameter or 01120 inch and bein'gappro'xiniately alnoh'in length.

The plunger 40 also includes an outer portion in which normally extends above the end of shell N to receive the actuating plunger 25 0f the extinguisher. One side of the outer plunger portion '50 f'orined with a hat 5! to reduc'e the erosssectionai area or this part of the plunger 170 Sfi-mCii-lfl y less than theccrresponding area of the opens-1g 7b in the she'll to allow free discharge of gas through this opening when the plunger has been driven inward-1y oi? the shell sufficiently to elren t ruptureand penetration of the partridge by its irmer end portion it. In addition, the re- '=aininder of the-plunger portion '59 .i's-relieved with respect to the intermediate portion 44 to provide 4 a transverse shoulder 52 at the upper end of plunger portion 4|, satisfactory results having been obtained with the radius of this portion of the plunger approximately .0025 inch less than the radius of the sealing portion 4 l In operation, the pressure cartridge unit comprising the cartridge l3 with the shell 33. and .plu'ng-er'de completely sealed with'relation thereto is mounted as shown in *Fig: 2 with the upper portion 31 of shell 33 received in socket member I7 and with the upper plunger portion extending above the upper end of the shell, the unit being clamped in this position by tightening thumbscrew 23. Prior to use of the device, the relationship of the parts is as shown in Fig. 2, and it will be noted that in this position, the intermediate plunger portion 41 is tightly received in the opening 36 in shell 33, thus elfecti'vely' sealing the interior of chamber 35, the passages 46, 41 and 48, and the seal 30 against the access of dint or moisture. The parts may be retained in-these positions for long periods of time without any loss in effectivenesseven though liquid from the extinguisher may drip or fall thereupon, -the operating. end of the cartridge, thus remaining effectively protected;

In order to use the extinguisher, it is inverted in the usual way andthe plunger cap 26 bumped on the floor or ground with'sufiicient force to drive the plunger '25a'gains't the adjacent end of plunger 40 and force the latter inwardly of the shell. When this occurs, the inner end '44 of the plunger will be driven against web 39 with sufficient force to rupture and penetrate the web, with. the sides of the lunger portion 44 seating tightly within the resulting opened end of the cartridge 1.3 as shown in Fig. 3. The compressed gas will accordingly be'released into the passage or bore 4'5 and then metered through the orifice 41 and bore 48 into the interior of chamber 35. At the same time, the intermediate plunger portion 4| will have been-driven inwardly of the shell sufliciently to clear the hole 36, thus opening this :hole for unrestricted how of gas'past the hat 5! into the interior of casing it to eifect discharge of the fire extinguishing material herein through hose l2. During this operation the gas flows out at a controlled rate determined by the accurately formed metering passage -47 which is predetermined so that the .gas will flow at a regulated rate such that no objectionable .ireezing will "a simple and efiective construction for a pressure cartridge unit which oifers substantial advantages. 'The unit includes only two component parts in addition to the cartridge, and they are or such simple design and construction that-they can 'bereadily manufactured at sufiiciently low cost to justify one-time use and disposal of the unit-rather than refilling. Although if it is desired to re-use the plunger and shell, this can be done since they are not damaged in use. Assembly'and replacement of the unit are also simple and easy, requiring only the insertion of the assembly in the cage; thereby simplifying the assembly and recharging of the extinguisher.

While the form of apparatus herein described constitutes a preferred .embodiment'oi the'i-nvention, it is "to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

, 1. A pressure cartridge unit adapted for use in a fire extinguisher of the character described comprising a sealed cartridge for containing compressed gas, said cartridge having a rupturable portion at one end thereof, a hollow shell tightly secured to said cartridge and extending beyond said end thereof to form therewith a sealed chamber overlying said rupturable portion, said shell having an opening in the outer end thereof opposite said rupturable portion of said cartridge, a plunger extending through said opening and having an inner portion of such diameter as to rupture and penetrate said rupturable cartridge portion to open said cartridge when said plunger is driven inwardly of said shell, said inner portion of said plunger having a restricted passage therein for metering the gas from said cartridge into said chamber following the penetration of said cartridge, said plunger including an intermediate portion adapted to cooperate with said end of said shell to normally seal said opening and to move out of sealing relation with said shell when said plunger is driven inwardly thereof.

2. A pressure cartridge unit adapted for use in a fire extinguisher of the character described comprising a sealed cartridge for containing compressed gas, said cartridge having a rupturable portion at one end thereof, a hollow shell tightly secured to said cartridge and extending beyond said end thereof to form therewith a sealed chamber overlying said rupturable portion, said shell having an opening in the outer end thereof opposite said rupturable portion of said cartridge, a plunger extending through said opening and having an inner portion of such diameter as to rupture and penetrate said rupturable cartridge portion to open said cartridge when said plunger is driven inwardly of said shell, said inner portion of said plunger having a restricted passage therein for metering the gas from said cartridge into said chamber following the penetration of said cartridge, said plunger including an intermediate portion adapted to cooperate with said end of said shell to normally seal said opening and to move out of sealing relation with said shell when said plunger is driven inwardly thereof, said plunger including an outer portion of substantially less cross-sectional area than said opening to provide for free discharge of gas from said chamber through said opening following said movement of said plunger.

3. A pressure cartridge unit adapted for use in a fire extinguisher of the character described comprising a sealed cartridge for containing compressed gas, said cartridge having a rupturable web at one end thereof, a hollow shell received over said end of said cartridge and tightly secured thereto to form therewith a sealed chamber overlying said web, said shell having an opening in the outer end thereof opposite said web, a plunger having an intermediate portion tightly received in said opening to seal the same, said plunger including an inner portion within said chamber and an outer portion, said inner portion being of such diameter as to rupture and penetrate said web to open said cartridge when said plunger is driven inwardly of said shell, said in ner portion of said plunger having a restricted passage therein for metering the gas from said cartridge into said chamber following the penetration of said web, and said outer portion of said plunger being of substantially less cross-sectional area than said intermediate portion to provide for free discharge of said gas from said chamber through said opening.

4. A pressure cartridge unit adapted for use in a fire extinguisher of the character described comprising a sealed cartridge for containing compressed gas, said cartridge having a rupturable web at one end thereof, a hollow shell tightly secured to said cartridge and extending beyond said end thereof to form therewith a sealed chamber overlying said web, said shell having an opening in the outer end thereof opposite said web, a plunger including a portion tightly received in said opening to seal the same, said plunger having an inner portion within said chamber of such diameter as to rupture and penetrate said web to open said cartridge when said plunger is driven inwardly of said shell, said inner portion of said plunger having a restricted passage thereinfor metering the gas from said cartridge into said chamber following the penetration of said web, said sealing portion of said plunger being of such dimensions as to move out of said opening for free discharge of gas therethrough from said chamber when said inner portion of said plunger has been driven inwardly of said shell to penetrate said web.

5. A pressure cartridge for use in a casing con taining material adapted to be discharged upon development of gas pressure therein following release of gas from said cartridge which comprises a weakened wall portion of said cartridge capable of being ruptured, a shell in sealed relation on said cartridge enclosing said wall por tion, a plunger carried by said shell in sealed relation therewith and in position to rupture said wall when driven thereagainst, said plunger having a rupturing portion adapted to seal against the opening in said cartridge wall upon being driven therethr'ough, a. metering passage extending through said plunger for controlling the flow of gas from said cartridge into the interior of said shell, and means forming a discharge passage from said shell opening upon actuation of said plunger.

6. A pressure cartridge unit for use in a casing containing material adapted to be discharged upon development of gas pressure therein following release of gas from said unit, comprising a cartridge having a weakened wall portion capable of being ruptured, a shell secured to said cartridge to form therewith a sealed chamber overlying said weakened wall portion, said shell having an opening therein, a plunger mounted in said opening to seal the same and including a portion adapted to rupture said weakened wall portion when driven thereagainst, said plunger including also a portion in position to be engaged from outside said shell for driving said plunger against said cartridge, said plunger having a restricted passage therein for metering the contents of said cartridge into said chamber following rupture of said wall portion by said plunger, and said plunger being proportioned to unseal said opening in said shell upon being driven into rupturing relation with said cartridge to effect free discharge of the contents of said cartridge from said chamber.

7. A pressure cartridge unit adapted for use in a fire extinguisher of the character described comprising a sealed cartridge for containing compressed gas, said cartridge having a rupturable portion at one end thereof, a hollow shell received over said end of said partridge and tightly secured thereto to form therewith a sealed charms ber, s d he ha i an o en in t e Outer end thereof opposite said rupturable portion of said cartridge, a plunger having an intermediate porti n t ht re i e n. ai ni to Seal the same, said plunger including an inner portion within said chamber and an outerportion, said inner portion being hollow and of such diameter as to rupture and penetrate said cartridge when said plunger is driven inwardly of said shell, said inner portion of said plunger having a metering passage connecting said hollow portion thereof with said Chamber, and said outer portion of said plunger being of substantially less crossseetional area than said intermediate portion to previde for free discharge of gas from said chains ber through said opening when said intermediate plunger portion is driven inwardly of said shell.

8. A pressure cartridge unit adapted for use in a fire extinguisher of the character described comprising a sealed cartridge for containing compressed gas, said cartridge having a rupturable web at one end thereof, a hollow shell tightly secured to said cartridge and extending beyond said end thereof to form therewith a sealed chamber overlying said web, said shell having an opening in the outer end thereof opposite said web, a plunger includin portion tightly received in said opening to seal the same, said plunger having an inner portion within said chamber of such diameter as to rupture and penetrate said web to open said cartridge when said plunger is driven inwardly of said shell, said inner portion of said plunger having a restricted passage therein for metering the gas from said cartridge into said chamber following said penetration of said Web, said sealing portion of said plunger being of such dimensions as to move out of said opening for free discharge of gas therethrough from said chamber when said inner portion of said plunger has been driven sufficiently inward o s d shell o net t sai w a a shoulder on said plunger inwardly of said sealing portion in position to seat on the inner surface of said end of said shell for preventing withdrawal of said plunger from said shell.

9. A pressure cartridge unit adapted for use in a fire extinguisher of the character described comprising a sealed cartridge for containing compressed gas, said cartridge having a readily rupturable web at one end thereof, a hollow shell tightly secured to said cartridge and extending beyond said end thereof to form therewith a chamber overlying said web, said shell havinga circular opening in the outer end thereof opposite said Web, a plunger including a cylindrical portion tightly received in said opening to seal the same, said plunger having an inner portion within said chamber of such diameter as to rupture and penetrate said web to open said cartridge when said plunger is driven inwardly of said shell, said plunger having a central bore open at said inner end thereof and having also a restricted passage connecting said bore with the interior of said chamber for metering the gas from said cartridge into said chamber following said penetration of said web, and said plunger having an outer portion of smaller cross-sectional area than said sealing portion to provide for free discharge of gas from said chamber through said opening in said shell following said rupture of said web.

EDWARD R. BORK.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 148,226 Great Britain 1922 299,096 Great Britain Oct. 22, 1928 

